1. Field of the Invention
This invention relates to inter-working method of wireless Internet (gateways) such as cellular, PCS and IMT-2000. It focuses on inter-working method that can support Internet service provided by foreign-wired network service provider including foreign mobile Internet service provider or foreign wireless Internet portal service provider who has wireless Internet contents. (Network of subscribed mobile service provider is referred to as the home domain, and the other network referred to as foreign)
2. Background of the Prior Art
When the subscribers are intended to be provided with wireless Internet service using mobile terminals, the mobile communications service providers authenticate the subscribers for data service by means of inter-working function (IWF) or a packet data service node (PDSN) and authentication server. The subscriber's terminal is connected to a wireless Internet portal gateway of the mobile communications provider by default when the subscriber's terminal requests to connect wirelessly to Internet again. Only the services of contents providers connected directly (not through wireless Internet gateway) to the mobile communications providers are provided according to provided wireless internet menus. That is, the current subscribers who need inter-working with providers, and opening of wireless network can be provided only with the contents connected directly to the mobile communications provider. As a result, inter-working service between networks is hindered to be spread out since there is not any solution to proper authentication, authorization, accounting, and so on for network inter-working.
Besides policy problems, the approval for mobile electronic commercial trade is exposed to the Internet. In conversion of wireless-based security to wire-based security (ex. WTLS→TLS) and the opposite conversion, security problems may rise at the wireless Internet gateway, which does not allow the traders to put confidence in the trade.
As a solution to security problems of the wireless Internet, a problem of data transmission efficiency within wireless section and the security problem can be solved at once if the mobile electronic commercial trade related contents portal providers manage the wireless Internet gateway directly.
However, in this management, authentication between the gateway servers, authorization, accounting management, etc. should precede in order to successfully inter-work with other networks (wireless Internet gateways of the mobile electronic commercial trade related contents providers) which subscribers want from the mobile communications providers. In other words, the subscribers could not inter-work with the wireless Internet gateways of either the other mobile communications providers outside of the mobile communications provider or the wired and wireless portal providers because its wireless Internet gateway (or proxy) performs protocol conversion, security protocol, and accounting to subscribers. It is because not only a policy problem but also a security and authentication problem, an authorization problem, a accounting problem, etc. arise in technology when interworking with the wireless Internet gateways at the same level. The conventional server-client type RADIUS (Remote Access Dial In User Service) is used usually in connection to wire Internet and has not be applied to the wireless Internet gateway. It can only authenticate the subscriber who connects to the mobile communications providers and cannot be applied to the wireless Internet gateway in the aspect of structure. The RADIUS is an old-fashioned authentication server for the relation between a server and clients and not an authentication server between networks.
Now DIAMETER protocol is described in brief The next generation AAA (Authentication, Authorization, and Accounting) protocol is the DIAMETER. The DIAMETER based AAA is a last draft state of IETF. The characteristics of the DIAMETER are described as follows.
First, it is server-to-server based operation. DIAMETER clients are network access server or router, Foreign Agent and Home Agent of Mobile IP protocol. And DIAMETER servers are AAAF(AAA server of Foreign) server, AAAB(AAA server of Broker) server and AAAH(AAA server of Home) server in multi-domain network.
Second, the whole communications between DIAMETER clients and server are encrypted and signed by means of a CMS(cryptograph message syntax) and a digital signature that is based on public key mechanism. In addition, the user's passwords included in DIAMETER message are encrypted to protect from hackers.
Third, the whole communications between DIAMETER server to server are authenticated by means of a security association of public key based.
Last, DIAMETER messages are encoded into Type-Length-Value field called Attribute or Attribute/Value Pair to deliver AAA information. Attribute is, for example, user's name(NAI), user's password and so forth.
As previous protocols, access is not possible across the among mobile Internet service provider's gateway (Example: WAP gateway) and mobile portal service provider's gateway which are provide portal service in foreign mobile Internet service provider's gateway. The RADIUS and DIAMETER application protocols have not been used in such wireless Internet networks to date. The protocols for the AAA service are required to support it among mobile Internet service provider's gateway and mobile portal service provider's gateway in the way to inter-working but the previous protocols described above cannot satisfy the requirement.
The protocol DIAMETER based proposed invented inter-working method has been developed to overcome the above-described problems. The DIAMETER protocol can be defined to be a light but expendable peer-based AAA protocol for AAA service for new policy, conventional technology such as PPP, and innovative technology such as roaming and mobile IP. The DIAMETER supports the greater length of the Attribute/Value. A DIAMETER server can transmit messages that a NAS can process, and support watch-dog communication-based transport that is fault-tolerant and reliable.
The DIAMETER is being employed as a next generation standard for authentication, authorization and accounting in the world at the time of this writing.